1. Field of the Invention
The present invention relates to the field of ophthalmology, and particularly provides a system and a configured device for preliminary diagnosis of ocular diseases, which is based on imaging of the eyes and on the diagnosis of ocular disorders, on the basis of the processing of these images and the reflection values of the retina and/or the pupil that they provide.
2. Description of Related Art
An estimate based on the National Health Survey (ENS 2007) indicates that at least 1.5% to 2.6% of the Chilean population has some visual impairment, of this percentage is estimated that at least ¼ of them has chronic defects classified as blindness. The world situation is not so different, and this reveals that there are at least 12 million children under the age of 10, which is the age group of preventive control, suffer from visual impairment due to refractive error (myopia, strabismus or astigmatism) in addition there are more severe cases like ocular cancer that affects 1 in 12,000 live births, which is usually seen in children up to 5 years old. All of these conditions and others, in most cases can be corrected without major complications with a preventive diagnosis and effective treatment in infants from birth to about 5 years old, preventing these disorders getting worse with time and treatment being too expensive, ineffective or simply being too late to be implemented.
Most of these problems could be detected at an early age, but require continuous medical supervision and examinations which are carried out with high-cost instruments that also require the presence of specialists to use them.
For the group of infants (0-5 years) which is the control group and primary diagnosis, there are two key problems in performing these tests: it is difficult to make that infants focus their gaze intently to any device that performs the test and also the ophthalmologist or pediatrician has only fraction of a second to capture the image before the pupil shrinks in response to the bright flash light. These problems lead to pediatricians are unable to detect ocular problems early, and therefore cannot effectively take preventive measures before the problem getting worse.
The red pupillary reflex is fairly well understood by ophthalmologists and pediatric specialists worldwide, and has been used as a diagnostic instrument around the world since the 60s. Normally, the light reaches the retina and a portion of it is reflected off the pupil by the choroid or posterior uvea, which is a layer of small vessels and pigmented cells located near the retina. The reflected light, seen from a coaxial instrument to the optical plane of the eye, normally present a reddish color, due to the color of blood and pigments of the cells, so this color can vary from shiny reddish or yellowish in people with light pigmentation to a more grayish red or dark pigmentation in people with dark pigmentation. In 1962, Bruckner (Bruckner R. Exakte Strabismus diagnostic bei 1/2-3 jahrigen Kindern mit einem einfachen Verfahren, dem “Durchleuchtungstest.” Ophthalmologica 1962; 144: 184-98) described abnormalities in the pupillary reflex as well as in quality, intensity, symmetry or presence of abnormal figures, therefore, pupilar red color test is also known as Bruckner test. Another similar test is the Hirschberg test, which uses the corneal reflex to detect misalignment of the eyes, which enables to diagnose some degree of strabismus (Wheeler, M. “Objective Strabismometry in Young Children.” Trans Am Ophthalmol Soc 1942; 40: 547-564). In summary, these tests are used to detect misalignment of the eyes (strabismus), different sizes of the eyes (anisometropy), abnormal growths in the eye (tumors), opacity (cataract) and any abnormalities in the light refraction (myopia, hyperopia, astigmatism).
The evaluation of the pupillary and corneal reflexes is a medical procedure that can be performed with an ophthalmoscope, an instrument invented by Francis A. Welch and William Noah Allyn in 1915 and used since the last century. Today, his company Welch Allyn, has products that follow this line as Pan Optic™. There are also photographic screening type portable devices for the evaluation of pupilar red color as Plusoptix (Patent application No. WO9966829) or Spot™ Photoscreener (Patent Application No. EP2676441A2), but the cost ranges between USD 100 to 500, they weigh about 1 kg and also require experience in interpreting the observed images.
With regard to state of the art, concerning computer applications for the prompt diagnosis of ocular diseases, the application No. FR2876570 A1 by Mawas, presents a process to obtain a picture with a camera and remit it in negative to a specialist ophthalmologist via email, in order to detect strabismus (Hirschberg test); however, this lacks the processing of the image, the immediately preliminary diagnosis and its application to mobile devices. The patent application No. US2013235346 A1 by Huang, points to a smart device application to obtain a set of pictures, at two specified working distances, and four orientations to run of photo-refraction tests, Bruckner and Hirschberg test, but requires masks that function like outlines on the screen, where the patient's face is fixed to obtain working distances, and there is no subsequent processing of images for a higher quality image.
The present invention is a practical and reliable solution for rapid diagnosis of ocular problems, which allows a preliminary examination only with the use of smart phones or tablet type devices, currently used by millions of people worldwide. The application can be run by parents, paramedics, pediatricians and ophthalmologists without the need for a more complex instrument or experience in the use of these, and effectively allows conducting a test to detect ocular problems. This application prototype was tested in 100 infants, from which 3 children with problems were detected, and which were referred to specialists who positively found ocular problems. The system allows to conduct a preliminary medical test regarding to the pupillary reflex (pupillary red color test or Bruckner test) and corneal reflex (Hirschberg test).